Working machine and method for working the ground

ABSTRACT

The invention relates to a working machine and a method for working the ground with the working machine, having a mast, along which, by means of a positioning means, a power rotary head is moved vertically, by which a telescopic Kelly rod having at least two Kelly bars is displaced and guided, wherein, for the purpose of torque transmission, the Kelly bars are provided on their external and/or internal sides with axially running drive keys as well as locking recesses on the drive keys and/or axial latch elements which are moved into the locking recesses for axially locking the Kelly bars or moved out of the locking recesses for unlocking. According to the invention provision is made in that by means of a control a locking state of the Kelly bars is checked automatically, wherein by the control the positioning means of the power rotary head and/or the main rope winch are actuated so that the Kelly bars are moved axially relative to each other, in that by means of a detection means a movement distance of the Kelly bars with respect to each other and/or an axial force during movement of the Kelly bars are axially detected, and in that depending on the detected movement distance and/or the detected axial force a locking state of the Kelly bars is ascertained by the control.

The invention relates to a working machine, in particular a construction machine, having a mast, along which, by means of a positioning means, a power rotary head is vertically movable, by which a telescopic Kelly rod having at least two Kelly bars is guided in a displaceable manner, wherein an outer Kelly bar designed for being supported on the rotary head and an inner Kelly bar are provided which comprises a rope suspension for a rope, by which the inner Kelly bar is vertically movable by means of a main rope winch, wherein, for the purpose of torque transmission, the Kelly bars are provided on their external and/or internal sides with axially running drive keys as well as locking recesses on the drive keys and/or axial latch elements which can be moved into the locking recesses for axially locking the Kelly bars or moved out of the locking recesses for unlocking, in accordance with the preamble of claim 1.

The invention further relates to a method for working the ground with a working machine, having a mast, along which, by means of a positioning means, a power rotary head is moved vertically, by which a telescopic Kelly rod having at least two Kelly bars is displaced and guided, wherein an outer Kelly bar that can be supported on the power rotary head or locked therewith and an inner Kelly bar are provided that is suspended on a rope, by which the inner Kelly bar is moved vertically by means of a main rope winch, wherein, for the purpose of torque transmission, the Kelly bars are provided on their external and/or internal sides with axially running drive keys as well as locking recesses on the drive keys and/or axial latch elements which are moved into the locking recesses for axially locking the Kelly bars or moved out of the locking recesses for unlocking, in accordance with the preamble of claim 9.

A Kelly rod is a telescopic tool rod which is composed of several tubular bar elements and has at least an outer Kelly bar and an inner Kelly bar. The inner Kelly bar, and thus the Kelly rod as a whole, is suspended on a rope, with the Kelly rod being guided by a Kelly guide and/or an annular rotary drive, also referred to as power rotary head. Via the Kelly rod a torque can be transmitted from the rotary drive to a ground working tool, in particular a drilling tool, that is mounted on the lower end of the inner Kelly bar. Through a corresponding outward-telescoping of the individual Kelly bar elements with respect to each other greater drilling depths can also be reached.

For the torque transmission the individual Kelly bar elements have on their external side and their internal side axially running stop ledges that serve for the torque transmission. Moreover, in specific axial positions, especially in a starting and end region, locking recesses or latch elements are provided, through which the Kelly bar elements can be secured axially with respect to each other. In this way, axial compressive forces can also be applied via the drill drive to the Kelly rod and therefore to the ground working tool. The outer Kelly bar can also be connected in an axially fixed manner to the drill drive.

Especially when working the ground in a discontinuous manner, for instance when producing a bore with a drilling bucket, the drilling bucket has to be moved repeatedly into the borehole and out of it again. Depending on the respective borehole depth the Kelly rod is accordingly telescoped inwards and outwards repeatedly. After the drilling bucket has been filled with removed ground material it has to be withdrawn from the borehole for emptying. For this purpose, the individual Kelly bar elements have to be unlocked again and retracted into each other. In this retracted position the Kelly rod can be withdrawn from the borehole together with the drilling bucket and pivoted to an emptying position. Afterwards, for a further drilling step the drilling tool is moved into the borehole again with a renewed outward-telescoping of the Kelly rod.

The inward- and outward-telescoping of a Kelly rod requires time and skill on the part of the operator of the drilling apparatus. Usually, the locking positions are concealed so that the operator of the drilling apparatus is not able to identify where the latch element and a locking recess are located. It is known that the position of the individual Kelly bar elements with respect to each other is displayed to the operator of the drilling apparatus on his operating monitor. However, such displays are very complex from a control engineering viewpoint and require a precise calibration of the individual drive components and of the positions of the Kelly rod before commencement of drilling.

Moreover, which type of Kelly rod is being used in which version must be entered into the control.

A method for monitoring a Kelly drill rod is known from DE 10 2012 019 850 A1. In this known method the detection of a rotational position of the bars is necessary. This requires an elaborate sensor arrangement which is generally prone to error in rough drilling operation.

An efficient method for a correct locking and unlocking of a Kelly rod can be taken from the generic EP 3 287 588 B1. For the purpose of locking, the Kelly bars are, on application of a certain torque, displaced axially with respect to each other until they rotate into a locking recess and are thereby locked. This rotation can be reliably detected by way of a temporarily occurring pressure change in the hydraulic drive system and therefore as a proof of locking.

During drilling operation an operator of the drilling apparatus may want to assure himself of a correct locking state of a Kelly rod for a secure drilling operation. This can take place through visual inspection of the Kelly rod or a manual test operation which is time-consuming and, at least in the case of less experienced operators of drilling apparatuses, does not rule out the risk of misjudgment.

The invention is based on the object to provide a working machine and a method for working the ground which enable a particularly efficient and secure working with a Kelly rod.

The object is achieved on the one hand by a working machine having the features of claim 1 and on the other hand by a method having the features of claim 9. Preferred embodiments of the invention are stated in the respective dependent claims.

The working machine according to the invention is characterized in that a control is provided which is designed for automatically checking a locking state of the Kelly bars, wherein by the control the positioning means of the rotary head and/or the rope winch can be actuated so that the Kelly bars are moved axially relative to each other, in that at least one detection means is provided, with which a movement distance of the Kelly bars with respect to each other and/or an axial force during movement of the Kelly bars can be detected, and in that depending on the detected movement distance and/or the detected axial force the control is designed to ascertain a locking state of the Kelly bars.

According to the invention a working machine is created, in which, irrespective of whether a locking process is carried out, the operator of the machine can reliably check the locking state of a Kelly rod at any time. This does not require visual inspection or specific experience of the machine operator.

Through simple actuation of the control this automatically carries out a checking process, in which the Kelly bars are moved axially with respect to each other. If, in doing so, the Kelly bars are in a locked state, the latch element and the locking recess have to abut axially within a maximum possible axial movement distance, which also results in an increase in the tensile force acting on the rope and/or in the axial pressure acting on the power rotary head. If such a state of axial movement and/or an increase in the axial force is established by the control, a correct locking state is identified. If this is not the case, the control can on the other hand establish that no correct locking is present.

By way of the invention a checking of the locking state of a Kelly rod can be realized in an automated way and with a high process reliability. At the same time, a machine operator can be relieved of this task, thereby also eliminating the risk of misjudgment by a human being. All in all, a drilling method can thus be carried out efficiently and with particular operational reliability.

A preferred embodiment of the working machine according to the invention resides in the fact that in the control a limit value for a maximum movement distance and/or a limit value for a minimum axial force are stored and in that in order to determine the locking state the detected movement distance can be compared with the maximum movement distance or the detected axial force can be compared with the minimum axial force. The maximum movement distance typically amounts to a few centimeters for each locking position and is mainly determined by the difference between the axial length of the locking recess and the axial length of the locking element that is rotated into the said recess. In particular, the maximum movement distance depends on the number of locking recesses so that total movement distance of up to more than one meter can result in the case of multiple Kelly bars.

The limit value or threshold value for the minimum axial force depends on the general displacement forces. If the locking element and the locking recess abut axially, a further axial movement is blocked and a force increase arises on the drive member that effects the axial movement. In particular, this can be established by way of force measuring elements, for instance located on the main rope winch or a positioning cylinder, or through a pressure increase in a hydraulic drive system.

In the simplest case the Kelly rod consists of only two Kelly bars, namely a tubular outer Kelly bar and an inner Kelly bar arranged therein in a displaceable manner. To reach greater drilling depths it is advantageous in accordance with a further development of the invention that the Kelly rod has one or several intermediate Kelly bars that are arranged between the outer Kelly bar and the inner Kelly bar. In particular, Kelly rods having three to five Kelly bars are preferred.

Basically, the working machine according to the invention with the Kelly rod can be used for a wide variety of operations. According to a further development of the invention it is particularly expedient that on the lower end of the inner Kelly bar a drilling tool, in particular a drilling bucket or an auger, is mounted in a releasable manner. Such drilling tools can be employed for discontinuous drilling, in which a Kelly rod has to be extended and retracted repeatedly.

According to a further embodiment variant of the invention it is advantageous that during movement of the Kelly bars the rotary head can be actuated by the control, wherein a predetermined torque can be exerted. In doing so, a torque is exerted onto the Kelly bars in such a way that the locking element is reliably rotated into a locking recess. In this way, it can be ensured that when a locking state is present the locking element and the locking recess make contact over as large an area as possible.

Basically, the movement distance and the axial force can be ascertained by way of corresponding distance sensors or force sensors. A particularly efficient determination of the axial force can be realized in that in order to detect the axial force a pressure increase in a hydraulic drive system can be detected.

Checking of the correct locking state of a Kelly rod can be carried out by the machine operator when necessary or at predetermined points in time or operating states. According to a further development of the invention it is particularly expedient that when detecting the locking state the position of the positioning means and/or a position of the rope can be saved in the control means. These collected data can be used to calibrate the Kelly rod and to verify the positions of lockings.

Another preferred embodiment of the invention resides in the fact that at least one input and/or determining means is provided, with which a type and/or size of the Kelly rod, a position of the positioning means for the power rotary head and/or a position of the rope can be input. In the simplest case, an input can take place via an input terminal. Alternatively, the positions can be detected automatically by means of sensors. In addition, it is possible to move the respective components into a defined starting position and to calibrate the working machine with these components.

The method according to the invention is characterized in that by means of a control a locking state of the Kelly bars is checked automatically, wherein by the control the positioning means of the power rotary head and/or the main rope winch are actuated so that the Kelly bars are moved axially relative to each other, in that by means of at least one detection means a movement distance of the Kelly bars with respect to each other and/or an axial force during movement of the Kelly bars are axially detected, and in that depending on the detected movement distance and/or the detected axial force a locking state of the Kelly bars is ascertained by the control. The positioning means can in particular be a feed drive of a feed carriage, on which the power rotary head is arranged and with which this can be displaced along a mast. The feed drive can in particular have a hydraulic cylinder or a pull winch.

The method according to the invention can in particular be carried out with a working machine as described previously. Accordingly, the advantages described beforehand can be achieved.

An advantageous method variant of the invention resides in the fact that for locking and/or unlocking, a ground working tool on the Kelly rod is placed onto the ground, in particular onto a borehole bottom. In doing so, the ground working tool and the inner Kelly bar firmly connected thereto are located in a defined position. By preference, the outer Kelly bar and/or an intermediate Kelly bar according to the invention can now be moved relative to the inner Kelly bar until the checking process is completed. Basically, the method according to the invention can be used for every application, in which a tool with a Kelly rod is required.

According to an embodiment variant it is especially preferred that a borehole is produced in the ground. The production of the borehole can be carried out by excavating the ground material.

According to a further embodiment variant of the invention provision is made in that the borehole is filled to form a foundation element. In a simple case, the foundation element can be filled with a pourable material, such as sand or gravel. It is preferred that the foundation element is formed by filling a hardenable mass, more particularly a concrete material.

According to a further development of the invention an efficient operating procedure can be accomplished in that by the control an automatic locking process is carried out if no locking state has been ascertained. In this process, the Kelly bars can be moved and rotated axially in a defined way with respect to each other, as is generally known for automatic locking.

The invention is explained further hereinafter by way of preferred embodiments illustrated schematically in the drawings, wherein show:

FIG. 1 a schematic partial view of a first working machine according to the invention;

FIG. 2 a schematic partial view of a second working machine according to the invention;

FIG. 3 a schematic broken-away illustration of a Kelly rod before unlocking; and

FIG. 4 a schematic broken-away illustration of the Kelly rod of FIG. 3 after locking.

The working machine 10 according to FIGS. 1 and 2 has in each case a substantially vertical mast 12 that possesses a mast head 14 each which is only depicted in FIG. 1 . Via a rope 52 driven by a main rope winch 50 and guided via deflection rollers 16 on the mast head 14 a Kelly rod 40 is suspended in a vertically displaceable manner along the mast 12.

According to the two embodiments pursuant to FIGS. 1 and 2 the Kelly rod 40 is in each case designed with an upper-lying outer Kelly bar 42, a lower-lying inner Kelly bar 46 and an intermediate Kelly bar 44 arranged in-between. On the upper end of the inner Kelly bar 46 a rope suspension 48 is provided, on which the rope 52 is designed for vertically displacing the inner Kelly bar 46 and also the further tubular Kelly bar elements.

At its upper end the outer Kelly bar 42 has a supporting collar 43, with which the outer Kelly bar 42 is supported on a power rotary head 30, i.e. an annular rotary drive. For the damping of shocks a damping means 32 with springs is arranged between the power rotary head 30 and the supporting collar 43 in the embodiment according to FIG. 1 . The power rotary head 30 on a carriage 18, and thus the outer Kelly bar 42, can be moved vertically along the mast 12 via a positioning means 20. In the embodiment according to FIG. 1 the positioning means 20 is designed as a hydraulic cylinder. To transmit the torque from the power rotary head 30 to the outer Kelly bar 42, and therefore to the Kelly rod 40 as a whole, drive keys 66 are arranged on the outer Kelly bar 42 on the external side thereof, as can be seen in FIG. 2 .

In a known manner, corresponding drive keys 66 or latch elements are also arranged on the other external sides and internal sides of the further Kelly bar elements. On a lower side of the inner Kelly bar 46 a pin-shaped connection element 49 is provided, with which a ground working tool 36 can be mounted in a torque-proof manner. In the embodiments according to FIGS. 1 and 2 the ground working tool 36 is designed as an auger.

In FIGS. 3 and 4 a simple Kelly rod 40 having an outer Kelly bar 42 and an inner Kelly bar 46 is illustrated. For the torque transmission from the outer Kelly bar 42 to the inner Kelly bar 46 the outer Kelly bar 42 has on its internal side at least one latch element 62 which rests in the circumferential direction against an axially running drive key 66 on the external side of the inner Kelly bar 46.

For an axial locking of the outer Kelly bar 42 and the inner Kelly bar 46 the latch element 62 on the outer Kelly bar 42 can be pressed lightly against the drive key 66 by applying a slight torque via the power rotary head 30 by means of a control. In this pressed-on position the outer Kelly bar 42 and the inner Kelly bar 46 can now be moved axially with respect to each other either via the positioning means 20 or the main rope winch 50 or by both. When the position illustrated in FIG. 4 is reached, the outer Kelly bar 42 with the latch element 62, on reaching a locking recess 68 designed as an axial recess in the drive key 66, rotates counter-clockwise in the circumferential direction into the locking recess 68 in the illustrated embodiment. In doing so, a rotation takes place between the outer Kelly bar 42 and the inner Kelly bar 46 which can be established by a first detection means, in particular a sensor means, as an indication for a locking.

According to the invention a correct locking state can be checked automatically by the control at any time. To this end, the positioning means 20 and/or the main rope winch 50 with the rope 52 are actuated via the control in such a way that a defined axial movement of the outer Kelly bar 42 with respect to the inner Kelly bar 46 takes place. If a correct locking is present, at least after a certain axial maximum movement distance that usually amounts to a few centimeters for each locking position and in any case does not exceed the axial length of a locking recess, the block-like latch element 62 has to abut axially against an axial stop 69 of the locking recess 68. A further axial movement of the outer Kelly bar 42 is now no longer possible. Moreover, this leads to an increased expenditure of force which can be detected as a pressure increase in the hydraulic system, by which the axial drive member is driven. This can be detected by the control which then displays that a correct locking is still present.

If, during the checking process by the control, the axial maximum movement distance is exceeded and/or if no increase of the axial force above a predetermined minimum axial force value is established, a reliable locking is no longer present. This state of the absence of locking can be displayed by the control to the operator of the drilling apparatus. The control can be actuated at any time by the operator of the drilling apparatus so that he is always reliably informed about the correct locking state. If no locking is established, an automatic locking process can preferably be carried out by the control. 

1. Working machine, in particular construction machine, having a mast, along which, by means of a positioning means, a power rotary head is vertically movable, by which a telescopic Kelly rod having at least two Kelly bars is guided in a displaceable manner, wherein an outer Kelly bar designed for being supported on the power rotary head and an inner Kelly bar are provided which comprises a rope suspension for a rope, by which the inner Kelly bar is vertically movable by means of a main rope winch, wherein, for the purpose of torque transmission, the Kelly bars are provided on their external and/or internal sides with axially running drive keys as well as locking recesses on the drive keys and/or axial latch elements which can be moved into the locking recesses for axially locking the Kelly bars or moved out of the locking recesses for unlocking, characterized in that a control is provided which is designed for automatically checking a correct locking state of the Kelly bars, irrespective of whether a locking process is carried out, wherein by the control the positioning means of the power rotary head and/or the main rope winch can be actuated so that the Kelly bars are moved axially relative to each other, in that at least one detection means is provided, with which a movement distance of the Kelly bars with respect to each other and/or an axial force during movement of the Kelly bars can be detected, and in that depending on the detected movement distance and/or the detected axial force the control is designed to ascertain the correct locking state of the Kelly bars.
 2. Working machine according to claim 1, characterized in that in the control a limit value for a maximum movement distance and/or a limit value for a minimum axial pressure are stored and in that in order to determine the correct locking state the detected movement distance can be compared with the maximum movement distance or the detected axial pressure can be compared with the minimum axial pressure.
 3. Working machine according to claim 1, characterized in that the Kelly rod has one or several intermediate Kelly bars which are arranged between the outer Kelly bar and the inner Kelly bar.
 4. Working machine according to claim 1, characterized in that on a lower end of the inner Kelly bar a ground working tool, in particular a drilling bucket or an auger, is mounted in a releasable manner.
 5. Working machine according to claims 1, characterized in that during movement of the Kelly bars the power rotary head can be actuated by the control, wherein a predetermined torque can be exerted.
 6. Working machine according to claim 1, characterized in that in order to detect the axial force a pressure increase in a hydraulic drive system can be detected.
 7. Working machine according to claim 1, characterized in that at least one input and/or determining means is provided, with which a type and/or size of the Kelly rod, a position of the positioning means for the power rotary head and/or a position of the rope can be input or determined.
 8. Working machine according to claim 7, characterized in that when detecting the correct locking state the position of the positioning means and/or a position of the rope can be saved in the control means.
 9. Method for working the ground with a working machine, in particular according to claim 1, having a mast, along which, by means of a positioning means, a power rotary head is moved vertically, by which a telescopic Kelly rod having at least two Kelly bars is displaced and guided, wherein an outer Kelly bar that is supported on the power rotary head and an inner Kelly bar are provided that is suspended on a rope, by which the inner Kelly bar is moved vertically by means of a main rope winch, wherein, for the purpose of torque transmission, the Kelly bars are provided on their external and/or internal sides with axially running drive keys as well as locking recesses on the drive keys and/or axial latch elements which are moved into the locking recesses for axially locking the Kelly bars or moved out of the locking recesses for unlocking, characterized in that by means of a control a correct locking state of the Kelly bars is checked automatically, irrespective of whether a locking process is carried out, wherein by the control the positioning means of the power rotary head and/or the main rope winch are actuated so that the Kelly bars are moved axially relative to each other, in that by means of at least one detection means a movement distance of the Kelly bars with respect to each other and/or an axial force during movement of the Kelly bars are detected, and in that depending on the detected movement distance and/or the detected axial force the correct locking state of the Kelly bars is ascertained by the control.
 10. Method according to claim 9, characterized in that for the purpose of checking, a ground working tool on the Kelly rod is placed onto the ground.
 11. Method according to claim 9, characterized in that a borehole is produced in the ground.
 12. Method according to claim 11, characterized in that the borehole is filled to form a foundation element.
 13. Method according to claim 9, characterized in that by the control an automatic locking process is carried out if no correct locking state has been ascertained. 